I. Field of the Invention
The present invention relates generally to medical instruments and, more particularly, to an illuminated ophthalmic membrane pick assembly.
II. Description of the Prior Art
Ophthalmic surgery usually requires the introduction of instruments into the interior of the eyeball. An opening is formed in the eyeball and sometimes a cannula is inserted into the opening. Thereafter, instruments are inserted through the eye opening so that an end of the instrument is within the interior of the eyeball.
In many types of ophthalmic surgery it is necessary to simultaneously insert multiple medical instruments into the interior of the eyeball. In many instances, each instrument requires its own scleral opening and own cannula although combination instruments have been previously known.
One such type of combination instrument comprises an illuminated membrane pick. These previously known illuminated membrane picks typically comprise an elongated housing adapted to be manually manipulated by the surgeon. A probe extends outwardly from one end of the housing and is dimensioned for insertion through a cannula positioned through the sclera. A membrane pick is then secured to the free or distal end of the probe while an optical fiber mounted within the probe provides illumination in the interior of the eye.
One disadvantage of this previously known illuminated membrane pick is that the membrane pick is always in an exposed and operable position once positioned within the eye. The pick is commonly used to dissect membranes, remove layers of scar tissue and the like. One disadvantage of these previously known illuminated membrane picks, however, is that since the pick is always in an exposed and operable position, movement of the pick within the interior of the eye can result in unintentional damage and iatrogenic openings in the eye. In some cases, the membrane pick even damages the sclera as the pick is inserted through and removed from the cannula.
The present invention provides an illuminated ophthalmic membrane pick which overcomes all of the above-mentioned disadvantages of the previously known devices.
In brief, the assembly of the present invention comprises an elongated housing having a longitudinally extending throughbore. An elongated tubular probe has one end secured to the housing in alignment with the housing throughbore and this probe is dimensioned for insertion through a cannula into the interior of an eyeball. A membrane pick is fixedly secured to the free or distal end of the probe so that the free end of the membrane pick overlies the free end of the probe.
An elongated optical fiber is longitudinally slidably disposed through both the housing throughbore and the probe. A button is then slidably mounted to the housing and mechanically fixed to the optical fiber so that the button and optical fiber move in unison with each other.
The button is operable to move the optical fiber between a retracted position and an extended position. In its extended position, an end of the optical fiber protrudes outwardly from the probe and laterally or radially outwardly displaces the free end of the membrane pick such that the free end of the membrane pick is nested against the side of the optical fiber. Conversely, in its retracted position, the optical fiber is nested within the interior of the probe.
In its extended position, the optical fiber effectively shields eye tissue from the membrane pick to prevent damage to the eye during movement of the pick within the interior of the eye. While in its extended position, the optical fiber is fully operational and provides illumination to the interior of the eyeball.
Conversely, in its retracted position, the end of the optical fiber is retracted away from the optical pick such that the optical pick overlies the free end of the probe and is in an exposed and operable position for membrane dissection and other medical procedures. While in its retracted position, however, the optical fiber continues to provide illumination from a light source to the interior of the eye.